The present invention relates to an electronic gaming machine and in a particular an electronic gaming machine using a primary game and a second bonus game. The invention has been developed primarily for use as an electronic gaming machine and will be described hereinafter by reference to this application.
The following discussion of the prior art is intended to present the invention in an appropriate technical context and allow its advantages to be properly appreciated. Unless clearly indicated to the contrary, however, reference to any prior art in this specification should not be construed as an express or implied admission that such art is widely known or forms part of common general knowledge in the field.
Conventional gaming machines typically involve awarding prizes to a player according to predetermined combinations of game symbols that appear on an array of game squares displayed on a screen, typically organised into three rows and five columns (a 5×3 array). Other arrays, such as a 3×3 or 4×3, may be used. Each gaming machine randomly selects the game symbols that appear on the array, each column of the array being a “reel”.
In an electronic gaming machine, the mechanical reels are replaced with video images of the reels, which are displayed on a video display screen. The electronic gaming machine has an internal electronic game controller, typically a computer, that controls the display of images on the video display screen so that the reels are visibly spun on the screen to simulate a physical reel of a traditional gaming machine. Electronic gaming machines are also more versatile in presenting game information, varying the probabilities for a player to win a prize and varying the type of game that is played.
A primary type of electronic gaming machine offers a main or base game having multiple sets of reels to permit a player to play several reels at the same time, depending on the amount that is wagered or bet by the player. For example, a gaming machine could offer four reel sets each having 50 pay lines available for selection by the player. By wagering a suitable amount, such as 200 credits, the player can play all 50 pay lines and thus all four reel sets. An electronic gaming machine may also offer an ante-bet feature, where the player makes further bet(s) each game that permits access to certain additional feature games or enhancements in the base game that otherwise be unobtainable. For example, a player could bet an extra 50 credits in addition to an initial bet of 100 credits that trigger an extra 10 free games when the free game feature is triggered that would not ordinarily be awarded without that extra ante-bet. In another example, a bet of an extra 100 credits adds further wild symbols to the base game and/or feature game reels that would not ordinarily be awarded without that extra ante-bet. In a further example, a bet of an extra 150 credits buys an additional reel in the base game that multiplies prizes for winning combinations, the extra reel not ordinarily being awarded without that extra ante-bet.
Traditionally, it is commonplace for bonus or “feature” games being provided by an electronic gaming machine in addition to the base or main game, whereby the feature game is activated by a trigger event during play of the base game and offered free to the player. Therefore, once a feature game is triggered, there is no amount that needs to be wagered for the player to play the feature games. In other words, while some feature games require an extra or ante-bet to qualify for additional features, traditionally the feature games are played without the player having to make an extra or side bet in addition to the original amount bet to play the base game. Once the free feature games have been played, the electronic gaming machine resets itself and returns the player back to the base game. This standard structure to game play limits the variation in the play of the electronic gaming machine. Consequently, it is difficult to retain player interest because there is no apparent incentive for the player to continue playing the same electronic gaming machine once the player becomes familiar with the feature game and the main game.
It is an object of the present invention to overcome or substantially ameliorate one or more of the disadvantages of prior art, or at least to provide a useful alternative.
It is an object of the invention in at least one preferred form to provide an electronic gaming machine and a method for controlling an electronic gaming machine that encourages player interest.